Hendrik Moes

Cytokine Production by Monocytes, NK Cells, and Lymphocytes Is Different in Preeclamptic Patients as Compared with Normal Pregnant Women

Objective. To measure cytokine production in ex vivo stimulated leukocyte populations of women with normal pregnancy and those with preeclampsia. Methods. Whole blood from preeclamptic and normal pregnant women was stimulated with LPS or PMA/Ca-ionophore. The percentages of IFNγ and IL-2, 4, and 10 producing lymphocytes and NK cells and the percentages of TNFα, IL-1β, and IL-12 producing monocytes were measured by flowcytometry. Results. In women with preeclampsia, there was a significantly increased percentage IL-4 producing cytotoxic T cells. Also, a significant decreased percentage IL-2 producing T helper cells and IL-12 producing monocytes was seen as compared with normal pregnancy. Conclusion. Th1 cytokine production of lymphocytes and monocytes appears to be decreased in our group of preeclamptic patients compared with normal pregnant women.

Cytokine production by natural killer lymphocytes in follicular and luteal phase of the ovarian cycle in humans.

PROBLEM: The aim of this study was to test the hypothesis that, during luteal phase of the ovarian cycle, as compared with follicular phase, the cytokine productive capacity of peripheral natural killer (NK)‐lymphocytes in humans is shifted towards a “Th2‐type”‐like response.
 METHOD OF STUDY: Intracellular Th1 and Th2 cytokine production by in vitro activated peripheral NK‐lymphocytes in a whole blood preparation of the follicular and the luteal phase of the ovarian cycle was measured by flow cytometry.
 RESULTS: There was no difference in interferon (IFN)(‐γ, interleukin (IL)‐2, IL‐4, and IL‐10 cytokine production in activated NK‐lymphocytes when comparing luteal phase with follicular phase of the ovarian cycle. However, there was a significant increase in peripheral NK‐lymphocyte number in luteal phase compared with follicular phase.
 CONCLUSION: The cytokine productive capacity of peripheral NK‐lymphocytes is not shifted towards a “Th2‐type”‐like response in the luteal phase as compared with the follicular phase of the ovarian cycle in humans.

Total white blood cell counts and LPS-induced TNFα production by monocytes of pregnant, pseudopregnant and cyclic rats

Pregnancy in the rat may be associated with an activated innate immune system. Therefore, we investigated monocyte function as well as total white blood cell (WBC) counts during the follicular phase of the ovarian cycle, pregnancy and pseudopregnancy in the rat. Rats were equipped with a permanent jugular vein cannula, and 0.43 ml blood samples were taken from this cannula during the 4 days of the regular oestrus cycle of the rat (n=12). Thereafter, six rats were rendered pregnant, and the other six rats were rendered pseudopregnant according to standard methods. Blood samples were withdrawn from the cannula on days 4, 7 and 11 of pseudopregnancy and on days 4, 7, 11 and 20 of pregnancy. From each blood sample, 0.4 ml was stimulated with lipopolysaccharide (LPS) and monocyte intracellular cytokine production measured using flow cytometry. 30 microl of the blood was used to measure WBC counts and differential WBC counts. The results showed that the number of WBC was significantly increased only on day 11 of pregnancy compared with the follicular phase, and that this was due to the increased numbers of polymorphonuclear (PMN) cells. The percentage of TNF alpha-producing monocytes was increased on all days of pseudopregnancy and on day 11 of pregnancy. The fact that the percentage of monocytes producing TNF alpha upon an LPS stimulus was increased during the post-implantation phase of pregnancy and during pseudopregnancy as compared to the follicular phase may indicate that these conditions are proinflammatory conditions. For the post-implantation phase of pregnancy, this is once more stressed by the increased numbers of WBC and PMN.

Effects of Food Restriction on Glucose Tolerance, Insulin Secretion, and Islet-Cell Proliferation in Pregnant Rats

Pregnancy is associated with increased glucose-stimulated insulin secretion and increased pancreatic islet-cell proliferation. In the present study it was investigated whether increased food intake, as occurs during pregnancy, is involved in the regulation of these phenomena. From Day 0 of pregnancy, rats received each day the mean amount of food they consumed daily during the estrous cycle prior to conception. This food restriction regime resulted in lower maternal body weight, and in lower fetal weight on Day 20 of gestation, but did not affect fetal survival. Food-restricted rats showed decreased insulin responses to an i.v. glucose challenge on Day 13, and lower islet-cell replication rates on Day 14 of pregnancy than pregnant rats fed ad lib. Plasma lactogenic activity in food-restricted animals was increased on Days 11 and 13; plasma progesterone levels were unchanged, but plasma leptin concentrations declined progressively during food restriction. Glucose tolerance was normal, suggesting that food restriction improved insulin action. On Day 20 of pregnancy, insulin responses were similar in food restricted and ad lib-fed rats; glucose tolerance was still unchanged. It thus seems that the improved insulin action as present on Day 13 had disappeared on Day 20. Also on Day 20, lactogenic activity as well as progesterone concentrations were similar in food-restricted and ad lib-fed rats. It was concluded that increased food intake plays an important role in the stimulation of islet-cell proliferation and insulin secretion, as well as in the diminished insulin action during the second week of rat pregnancy.

THE PROLONGED ACTION OF THE LHRH AGONIST BUSERELIN (HOE-766) MAY BE DUE TO PROLONGED BINDING TO THE LHRH RECEPTOR

Hemi-pituitary glands of ovariectomized rats were superfused for 4 h with either LHRH or the analog buserelin (HOE 766) at several concentrations, and thereafter with medium only for another 1.5 h. In a further experiment glands were exposed for 2.5 h to LHRH or buserelin at a single concentration (5 ng/ml) and subsequently for another 2.5 h to either the same agonist (LHRH or buserelin) alone (5 ng/ml), the agonist plus an LHRH-antagonist (ORG 30093, 1000 ng/ml), the LHRH- antagonist alone, or medium alone. LHRH and buserelin stimulated gonadotropin release equally well. After cessation of this stimulation, the gonadotropin release by the buserelin-treated pituitary glands and the glands, treated with the highest dose of LHRH (1000 ng/ml), continued, while the release by the glands, treated with the lower doses of LHRH, declined. The LHRH-antagonist completely blocked the release of LH, stimulated by buserelin or LHRH, as well as the prolonged activation of the release, caused by buserelin pre-treatment. In a superfusion experiment with pituitary cell aggregates of 14-day-old intact female rats, buserelin stimulated the release of LH much more effectively than LHRH itself. Moreover, the release caused by buserelin declined more slowly after cessation of the stimulation. Finally, in a pituitary cell monolayer culture the Kds of LHRH, buserelin and the antagonist were determined as 4.7 X 10(-9) M, 2.4 X 10(-10) M and 4.6 X 10(-9) respectively. It was concluded that the estimates of the potencies of LHRH and buserelin depend on the choice of the test-system. It is suggested that the long duration of action of buserelin is at least partly due to prolonged binding to the LHRH-receptor.

Glomerular Immunoglobulin Deposits Induce Glomerular Inflammation in Pregnant but not in Non‐pregnant Rats

PROBLEM: Does an inflammatory stimulus evoke a more intense inflammatory response in pregnant rats as compared with non‐pregnant rats?

Effect of in vivo pre-treatment with oestradiol and either GnRH, GnRH agonistic analog or GnRH antagonistic analog on GnRH-stimulated secretion of LH in vitro

In vivo treatment with GnRH or with GnRH agonistic analog (AG), but not with GnRH antagonistic analog (ANT), depleted the LH stores of the rat pituitary gland. This depletion was potentiated by oestradiol. Oestradiol augmented the in vitro LH response of the pituitary gland to GnRH. This augmenting effect of oestradiol became smaller with increasing rates of in vivo administration of GnRH or AG, but not with ANT. With respect to both depletion of the LH stores and suppression of the augmenting effect of oestradiol, AG ist about 20 times as potent as GnRH.

Effect of the TRH analogue, CG 3703, on prolactin secretion in the pseudopregnant rat

The effect of the TRH analogue, CG 3703 (AG), on secretion of prolactin (Prl) was studied in pseudopregnant rats. AG stimulated Prl secretion of incubated pituitary glands in the presence of 5.10(-8) M dopamine (DA) but not in the presence of 0 or 10(-6) M DA. AG did not inhibit the in vitro secretion of Prl. AG postponed the peaks of Prl which were generated between 0100 and 1200 h (delay after 500 micrograms AG: 3-4 h); the height of these nocturnal Prl peaks was not affected by AG. AG did not induce Prl secretion during the phase of low Prl secretion (the interphase) between 2000 and 0100 h. The DA-release blocking drug, HA 966, induced peaks of Prl during the interphase. These peaks were as high as spontaneous nocturnal Prl peaks and were blocked by AG. The results show that AG has two opposite effects on Prl secretion: a direct, stimulating effect, which is modulated by DA, and an indirect inhibitory effect, which is probably executed by DA, released by AG from the tuberoinfundibular DA neurons.